Bicyclo[4,1,0]heptane-2,4-dion derivatives, its synthetic intermediates and process for the manufacture thereof

ABSTRACT

Compounds represented by general formulas (I) and (II), useful as the intermediates for agricultural chemicals, particularly herbicidal compounds, wherein R 1  and R 2  represent each hydrogen, alkyl or COOR 3  :R 3  represents alkyl: and R 4  represents alkyl.

This application is a 371 of PCT/JP92/00084, filed Jan. 28, 1992.

FIELD OF THE INVENTION

The present invention relates to bicyclo[4,1,0]heptane-2,4-dionderivatives useful as an intermediate, the intermediates for thesynthesis thereof and the process for the manufacture thereof.

BACKGROUND ARTS

2-substituted benzoyl-1,3-cyclohexanediones have been known effective asweed killers, and the ones having various subsituents and/or chemicalstructures have been proposed.

It is an object of the present invention to provide effective compoundsas the intermediates for synthesizing herbicidal compounds.

DISCLOSURE OF THE INVENTION

The present invention is directed to a compound represented by thegeneral formula (I): ##STR1## wherein R¹, R² denotes each independentlyhydrogen, alkyl or --COOR³, and R³ denotes alkyl, and the process forthe manufacture thereof, and a compound represented by the generalformula (II): ##STR2## wherein R¹, R² are as defined above and R⁴denotes alkyl, and the process for the manufacture thereof.

The compound of the general formula (I) is prepared from the compound ofthe general formula (II) according to the process shown below; ##STR3##wherein R¹, R² and R⁴ are as defined above.

The reaction shown above is accomplished by reacting a cyclopropanederivative of the general formula (II) in an adequate solvent and in thepresence of a base.

As the solvent described above, alcohols such as methanol and ethanolcan be used, and the sodium alcoholate or potassium alcoholate thereofcan be used as the base described above.

The reaction can be accomplished at a temperature in a range of fromroom temperature to 150° C., and preferably at the boiling point of thealcohol used. One to five times amount in mole of the base relatively tothe mole of the cyclopropane derivative used, and preferably 1 to 2times in mole, is used for the reaction.

Them cyclopropane derivatives of the general formula (II) can bemanufactured by reacting a ketone of the general formula (III) with anester of the general formula(IV) in the presence of a base according tothe process shown below; ##STR4## wherein R¹, R² and R⁴ are as definedabove, and Hal denotes halogen.

The foregoing reaction is normally accomplished in an adequate solvent.As the solvent, benzene, toluene and the like can be used besidesalcohols, however, it is the most preferable to use alcoholate as a basein alcohol. In the reaction, bicyclic compounds represented by thegeneral formula (I) can be prepared without isolating cyclopropanederivatives of the formula (II) when more than 2 moles of alcoholate isused. The halogen is preferably chlorine.

As shown below, a compound of the general formula (VI) having herbicidalactivity can be readily prepared by reacting the bicyclic compound ofthe general formula (I) with chloride benzoate of the general formula(V). ##STR5## wherein Xn denotes a substituent.

It is described in the International Publication No. WO 91/00260 Gazettethat the compound represented by the general formula (VI) showsherbicidal activity.

The compound specified in this invention may have the tautomers as shownbelow. ##STR6##

The chemical structures of the compounds according to the invention andother compounds were determined by using IR, NMR, MS and otheranalytical apparatuses.

BEST MODE FOR CARRYING OUT THE INVENTION

Now, the present invention is practically explained with reference toExamples and Practical Examples.

EXAMPLE 1 (2-acetylcyclopropyl)diethyl methylmalonate ##STR7##

In 25 ml of ethanol was added 5.15 g of powdered sodium ethylate, thendissolved. To the solution, 13.2 g of diethyl methylmalonate was addedat room temperature, then 9.5 g of 5-chloro-3-pentane-2-on (90% purity)was further fed dropwise thereto for 30 min. at a temperature of from 0°to 10° C. After reacting the solution for 3 hours at room temperature,ethanol therein was removed by distillation under reduced pressure, thenan extraction was made with ethyl acetate after pouring the solutioninto ice water. The extract was dehydrated with magnesium sulfate, thenthe solvent therein was removed by distillation, affording 17.3 g of theobjective product (98.5% purity) by distillation under reduced pressure.Boiling point of the product was in a range of from 130° to 135° C., andall of the compound obtained were in trans-form.

EXAMPLE 2 Cis- and trans-5-ethoxycarbonyl-5-methylbicyclo[4, 1,0]heptane-2,4-dion (Compound No. 3 and 1) ##STR8##

330.7 g of (2-acetylcyclopropyl)diethyl methylmalonate of the formula(II), wherein R¹ is CH₃, R² is CO₂ C₂ H ₅, and R³ is C₂ H₅, was addedinto 975.6 g of 14% sodium ethylate solution in ethanol, then thesolution was heated to reflux for 3 hours. After cooling the solution,it was poured into cool aqueous solution of hydrochloric acid, thenextracted with ethyl acetate. The extract was then washed with saturatedbrine. After dehydrating the extract with magnesium sulfate, the solventwas removed by distillation therefrom, affording 87.6 g of the transform compound of the formula (I), wherein R¹ is CH₃ and R² is CO₂ C₂ H₅,in whitish crystals by adding ether into the remained solution.

The solution filtered was further separated by using silica gelchromatography to obtain 8.1 g of the trans-form compound and 27.8 g ofthe cis-form compound of the formula (I), wherein R¹ is CO₂ C₂ H₅ and R²is CH₃.

EXAMPLE 3 Cis- andtrans-5-ethoxycarbonyl-5-methylbicyclo[4,1,0]heptane-2,4 -dion (CompoundNo. 3 and 1) ##STR9##

In 20 ml of ethanol was added 3.52 g of powdered sodium ethylate, thendissolved. To the solution, 4.5 g of diethyl methylmalonate was added atroom temperature, then 3 g of 5-chloro-3-pentene-2-on (97.5% purity) wasfurther added thereto at a temperature of from 0° C. to 10° C. Afterreacting the solution for 1 hours at room temperature, the solution washeated to reflux, for 24 hours. Then the solution was treated accordingto the procedure in Example 1, affording 1.29 g of the trans-formcompound and 0.41 g of the cis-form compound.

The representative examples of the compounds according to the presentinvention including the compound obtained in the Examples describedabove are illustrated in Table 1.

                  TABLE 1                                                         ______________________________________                                               Chemical Structure                                                      ##STR10##                                                                              ##STR11##                                                                                        ##STR12##                                        No.      R.sup.1    R.sup.2     [ ] m.p. °C.                           ______________________________________                                        1        CH.sub.3   CO.sub.2 C.sub.2 H.sub.5                                                                  [110-112]                                     2        CH.sub.3   H           [100-103]                                     3        CO.sub.2 C.sub.2 H.sub.5                                                                 CH.sub.3    [105-108]                                     4        CH.sub.3   CO.sub.2 CH.sub.3                                                                         [122-124]                                     5        CH.sub.3   CO.sub.2 C.sub.3 H.sub.7 (i)                              ______________________________________                                    

PRACTICAL EXAMPLECis-3-(4-chloro-2-nitrobenzoyl)-5-methylbicyclo[4,1,0]heptane-2,4-dion##STR13##

(1) 5.0 g oftrans-5-methyl-5-ethoxycarbonylbicyclo[4,1,0]heptane-2,4-dion of theformula (I), wherein R¹ is CH₃ and R² is CO₂ C₂ H₅, was dissolved in 50ml of methylene chloride, then 2.65 g of triethylamine was further addedthereto. After cooling the solution to 10° C., 5.24 g of4-chloro-2-nitrobenzoylchloride was added to the solution and stirredfor 2 hours at room temperature. After washing the reacting solutionfirstly with diluted hydrochloric acid and then water, the solution wasdehydrated with magnesium sulfate, and the solvent therein was removedby distillation under reduced pressure. The residues were dissolved into50 ml of acetonitrile, then added with 0.15 g of potassium cyanide and2.45 g of triethylamine, and stirred for one night at room temperature.After removing the solvent therein under reduced pressure, methylenechloride was added thereto, then the solution was washed firstly withdiluted hydrochloric acid then water, and dehydrated with magnesiumsulfate. After removing the solvent in the solution, 9.7 g oftrans-3-(4-chloro-2-nitrobenzoyl)-5-methyl-5-ethoxycarbonylbicyclo[4,1,0]heptane-2,4-dionwas obtained.

(2) 73 ml of 1 N NaOH was added to the compound obtained in (1), thenthe solution was stirred for 24 hours at room temperature. After coolingthe solution to a temperature range of from 5° C. to 10° C., 110 ml ofethyl acetate was added thereto, and 48.4 ml of 1 N HCL was further feddropwise thereto. After stirring the solution for 2 hours, the organiclayer was separated and washed with saturated brine, dehydrated withmagnesium sulfate, then the solvent therein was removed by distillationunder reduced pressure. To the remained solution was added 15 ml ofmethanol and cooling the solution, affording 4.7 g of the objectiveproduct in whitish crystals. The melting point of the product was in arange of from 104° C. to 108° C.

FIELD OF INDUSTRIAL USE

The compounds according to the present invention are useful as theintermediates for the manufacture of agricultural chemicals and thelike, and particularly the intermediates for herbicidal compounds.

What we claim is:
 1. A compound represented by the formula (I):##STR14## wherein R¹ and R² denote each independently hydrogen, C₁ -C₆alkyl or --COOR³ and R³ denotes C₁ -C₆ alkyl, with the proviso that bothR¹ and R² cannot denote --COOR³.
 2. A process for preparing a compoundrepresented by the formula (I): ##STR15## wherein R¹ and R², denote eachindependently hydrogen, C₁ -C₆ alkyl or --COOR³ and R₃ denotes C₁ -C₆alkyl with the proviso that both R¹ and R² cannot denote --COOR³characterized in that the compound is prepared by forming a ring closurein a compound represented by the formula (II): ##STR16## wherein R¹ andR² are as defined above and R₄ denotes C₁ -C₆ alkyl.